Six months. 5,700 miles. One ocean. Ben Lecomte wants to be first to swim across Pacific.

Ben Lecomte, a 50-year old Frenchman turned Texan, will slip into the water on Sunday off the coast of Choshi, Japan, and start swimming. If all goes as planned, he won’t set foot on land for six months. In that time, he plans to swim through the largest collection of trash on the planet, great white shark migration areas, through jellyfish and storms and isolation and monotony.

In November, Lecomte hopes to paddle and kick all the way to San Francisco, becoming the first person to swim across the Pacific Ocean, an extraordinary transcontinental quest that’s equal parts adventure and science experiment.

“For me, swimming is a passion,” Lecomte explained in a recent interview. “But if it’s just swimming for pleasure, that’s limited. I need to have greater purpose and a bigger vision.”

It doesn’t get much bigger than the Pacific, the world’s largest pool and something Lecomte has been targeting for nearly 20 years. In 1998, he’d successfully crossed the Atlantic, which earned him a bit of fame. He appeared on The Oprah Winfrey Show and told her, “When I arrived after swimming the Atlantic, my first words were, ‘Never again.’ Then a few months after, I said, ‘No, I need to go back.’ It’s something that I need. It’s within me. I need to find another challenge and to push myself.”

It took nearly two decades to reach this point, with plenty of false starts and funding hiccups along the way. The scale and ambition of this crossing is much different than the Atlantic. The Japan-San Francisco trek will measure 5,500 miles, a staged attempt that will take 180 or so days. Swimming from Cape Cod to France in 1998 measured 3,700 miles over 73 days. That swim was never verified by Guinness World Records because Lecomte drifted off-course in a boat and didn’t necessarily resume his swims at the exact point he stopped them.

His new undertaking is a lot more involved with financial backing from companies like Seeker, the science-focused digital publisher, and Discovery. He’ll have an eight-person crew that will be collecting and studying data on both the ocean and Lecomte throughout the journey, picking up 1,000 or so water samples along the way. Lecomte will be accompanied by a 67-foot sailboat and each day, a smaller inflatable motorboat or kayak will lead him in the water, keeping him on-course.

Lecomte is aiming to swim eight hours each day, covering 40 miles of choppy waters, and then spending his nights recuperating on the sailboat. He’ll try to consume 8,000 calories each day, freeze-dried and canned foods on the boat and solely liquids during the swim. He’ll be outfitted like an electronics store. Lecomte will have a headset that allows him to stay in constant contact with the crew, a waterproof heart monitor that will track every beat, a bracelet that creates a magnetic field to repel sharks, and another on his ankle that measures radioactivity.

Lecomte and his team have partnered with more than a dozen research organizations, including NASA, Argonne National Laboratory and Woods Hole Oceanographic Institution, and they’ll be collecting samples to study water conditions, trash content and how the prolonged exposure affects Lecomte.

“My father taught me how to swim in the ocean when I was 5 years old,” said Lecomte, who was raised in France but now lives and trains in Austin, Texas. “So the environment and being in the open water has been very important to me my entire life. And now that I am a father, I look at it this as a way to do something for my children because I have seen a lot of changes in the ocean.”

The risks are different than the challenges. Lecomte and his crew will closely monitor the changing conditions, and he’ll wear a thick wet suit to help him navigate waters that could reach 50 degrees. In addition, they’ll utilize both magnetic and electric fields to ward off sharks.

“I used to ride a motorcycle in Paris, and I can guarantee you there’s much more risk in doing that than swimming in the ocean,” said Lecomte, a longtime architectural consultant who is now associate director of sustainability services for Progea, an environmental consulting firm.

His training has included six hours of continuous open water swimming each day, and he feels comfortable with the physical demands these next six months hold.

“But an adventure like this is really mind over matter,” he said. “I’m not trying to swim faster than anybody else. I’m just trying to log my time and my hours per day. What is important is knowing what you’re going to do with your mind.”

They key, he said, is not exerting mental energy on the inevitable struggles. He’ll have a game plan each morning before he gets in the water outlining exactly what he intends to occupy his mind for the ensuing eight hours. In fact, he’ll have specific mental exercises scheduled — one hour devoted to designing a building in his head, perhaps, followed by two hours recalling a favorite day. While he might think ahead to life moments waiting down the road, he’ll largely draw from specific memories, reliving them as vividly as possible.

“Maybe it’s a birthday party,” he said. “I try to remember every detail, smell, the noises, was it warm or cold? — just as much information as I can remember. Then it becomes easier for your mind to disassociate from your body. My mind can focus on a subject and my body can focus on what it needs to do.”

The first couple of weeks figure to be the toughest, he said, as his body adjusts to its new routine: avoiding sugars, waking up in the middle of the night to load up on calories, dropping into the cold water each morning when all he really wants it to do is sleep another two hours and let his tired muscles recover.

In addition to the scientific undertakings, Lecomte hopes his journey will draw attention to the state of the oceans. His route will take him right through the Great Pacific Garbage Patch, the giant mass of floating trash midway between Hawaii and California that some estimates to be larger than Texas.

The entire swim will be documented by Seeker.com, with streaming video from the boat, a multipart video series and a steady flow of social posts and dispatches, plus regular television updates on Discovery and a full-length documentary at some point next year.

When he crossed the Atlantic 20 years ago, his girlfriend, Trinah, was waiting on the other side and immediately accepting his marriage proposal. This time he’s avoided thinking much about what San Francisco will be like on the back-end or what long-distance challenges might lie ahead.

“I’m not going to eat any seafood for a long time after the swim, I can tell you that,” he said.

But there is one thing he knows he’s looking forward to. If all goes as planned, six months from now, the San Francisco coast line will be in sight, and his 17-year old daughter and 11-year old son will join Lecomte in the water, swimming alongside him for the final few hundred yards of his epic journey.

Rick MaeseRick Maese is a sports features writer for The Washington Post. He has written about the NFL since joining The Post in 2009, including three seasons as beat writer for the Washington Redskins. Follow